:o: Are there 8 or 16 plugs in a hemi (big drinking debate right now)

Are we talking old hemi or new hemi here?

Depends on who's buying the beer.

the newer hemi 1500s trucks, cars 2000-2006ish

8.......I'm 99.9% sure.

Actually its dual spark plugs in each cylinder so 16


Why dual spark plugs?

Michael E. Gemmel wrote: “Each cylinder has an ignition coil pack over one spark plug, and a regular plug wire connected to the other spark plug. Further, the coil pack also has a plug wire attached to it that extends to the opposite cylinder bank. It appears that each cylinder shares a coil pack with another cylinder. Each of the two plugs on a given cylinder is fired by a separate coil. One plug has a coil directly attached, and the other is fired via an ignition wire connected to a coil located on another cylinder on the opposite bank. The benefits would be one-half the number of coils (8 vs. 16) compared to each plug having its own coil, and of course less weight.”

“Cryptojoe” wrote: “Being the good Motech Graduate I am, I can say that the extra plug fires during the power stroke in order to more full burn the hydrocarbons. While this does add to NOx (oxides of nitrogen) and ozone emissions, it relieves the catalytic converter from becoming overwhelmed with unburned hydrocarbons. Unlike the Japanese systems of the late 1970s and early 1980s, which avoided the use of catalytic converters, the second ignition allows additional power in the down stroke while lowering the need of restrictive catalyst plates in the converter. This increases breathing, and in turn adds to horsepower output as well.

“As you may recall, in the 1980s Japanese manufacturers skirted trade restrictions concerning EPA standards for unburned hydrocarbons by place spark plugs either in the exhaust pipe (which fired with every piston ignition) or in the exhaust manifold (which fired each time their corresponding cylinder fired). Chrysler morphed this idea to include dual fired plugs on each cylinder, which allows the firing to take place closer to top dead center, and then again when the piston is on the back side of the power stroke.”

Actually its dual spark plugs in each cylinder so 16
Well,crap. Looks like I'm 100% wrong :o:

Actually, the reason they do it that way is because they are cheap :)

My dirtbike is a 4 stroke, but the plug fires on every revolution.

The ignition is triggered from the crankshaft position sensor... saved them from having to install a sensor on one of the camshafts.

Well,crap. Looks like I'm 100% wrong :o: I think you are only 99.9% wrong:D

who cares? it's a dodge

who cares? it's a dodge
:exactly:

:exactly: Actually, the reason they do it that way is because they are cheap :)

My dirtbike is a 4 stroke, but the plug fires on every revolution.

The ignition is triggered from the crankshaft position sensor... saved them from having to install a sensor on one of the camshafts.